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10 Awg for 32A STC?

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kaizday

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May 27, 2021
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I have two 8.63a Imp and another two 8.35a Imp, planning to parrallel them, so technically my max current can be as high as 34a, right?

most of the 'T' 4 to 1 connector rating is 30a. i saw this one rated for 50a, not sure if i can trust them. but let's say that i do get it and combine the 4 panels to a 10ft 10 awg cable to the inverter, do you think it is safe enough for my setup? is it just reduce my peak power or it cause any ??

tia
 
Just use 8 gauge and remove all doubt. Yes, higher rated MC-4 adapter and connectors (as well as photovoltaic wire) exist. You do pay a premium for them, that's why most people use series and higher voltage.

If it is mounted on your house, likely fire codes would prevent you from fudging the capacity ratings.
I do carry 40 amps of current over 10 gauge wire for short distances all the time, but codes are different. In my case, it's for testing, the wire does get warm, but not alarmingly so, more lukewarm.
 
4 panels in parallel, you should install in-line MC4 fuse/fuse holder for each panel.
 
Just John said:
Just use 8 gauge and remove all doubt. Yes, higher rated MC-4 adapter and connectors (as well as photovoltaic wire) exist. You do pay a premium for them, that's why most people use series and higher voltage.

If it is mounted on your house, likely fire codes would prevent you from fudging the capacity ratings.
I do carry 40 amps of current over 10 gauge wire for short distances all the time, but codes are different. In my case, it's for testing, the wire does get warm, but not alarmingly so, more lukewarm.
Click to expand...

thanks much.

they are on the ground, 'Will's style', laying on a couple of paver blocks lol.
 
What are the spec of the 60-cell and the 72-cell? If you parallel them using mismatch spec panel, the Voltage will be of one with lowest Voltage, the total Wattage not be the total of 4 panels either. I would use the fuse rating as spec on the panel.
solarpanelsvenue.com

Mixing solar panels – Dos and Don’ts • SOLAR POWER SECRETS

Mixing Solar Panels: Discover Now Dos and Dont's of Mixing the Same Types or Different Types of Solar Panels. Act Now to Save Your Money!
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Bud Martin said:
What are the spec of the 60-cell and the 72-cell? If you parallel them using mismatch spec panel, the Voltage will be of one with lowest Voltage, the total Wattage not be the total of 4 panels either. I would use the fuse rating as spec on the panel.
solarpanelsvenue.com

Mixing solar panels – Dos and Don’ts • SOLAR POWER SECRETS

Mixing Solar Panels: Discover Now Dos and Dont's of Mixing the Same Types or Different Types of Solar Panels. Act Now to Save Your Money!
solarpanelsvenue.com solarpanelsvenue.com
Click to expand...

yeah, i kinda know that i will loose some power, but i am trying to keep this project as low cost as possible.

the larger ones are 36V 315w and the smaller ones are 30V 260w. my inverter is capped at 50v i believe. hopefully i can peak at 1kw, hopefully.

btw, on the panel, there is only 'max fuse series', is the same applied for parallel?
 
Max fuse rating is what you do not want to go above, so you have 4 panels in parallel then you need 4 fuses one per panel as specified.
The fuse for each panel connected in parallel is for protection if for example if one panel shorted out which causes the current from the other 3 panels to be dumped into the shorted panel.
 
Just John said:
Yes, they perform better with air circulation.

Let me guess, something like this is what you are speaking of:

Click to expand...

lol, yeah, basically. i got that same brand, but with higher voltage and 1300w. this forum doesn't seem to want to deal with non UL GTI, so i didnt want to bring it up, but that's the only I could afford.

it's been doing ok with 2 panels setup, but now i am trying to figure the best way to add the additional 2 smaller panels i have laying around. amp rating is what kinda scare away from adding more panels as all i have is 10 gauge cables. so I'm very glad to hear that you were able to push 40a on 10 awg.

I'll probably will get some fuses as Bud Martin suggested to add a little peace of mind.
 
kaizday said:
lol, yeah, basically. i got that same brand, but with higher voltage and 1300w. this forum doesn't seem to want to deal with non UL GTI, so i didnt want to bring it up, but that's the only I could afford.

it's been doing ok with 2 panels setup, but now i am trying to figure the best way to add the additional 2 smaller panels i have laying around. amp rating is what kinda scare away from adding more panels as all i have is 10 gauge cables. so I'm very glad to hear that you were able to push 40a on 10 awg.

I'll probably will get some fuses as Bud Martin suggested to add a little peace of mind.
Click to expand...
Fuses or a circuit breaker are a good idea.
Pushing 32 amps max through 10 gauge wire isn't a problem. I've done 40 amps through 10 gauge for very extended periods of time (battery cell testing). Also not a problem. At 40 amps the wire will get warm to the touch, but not even close to hot. I would be more concerned with voltage drop if it is too long.
 
Since that inverter is grid-tie, I wonder what kind of leakage current on the exposed terminals of the unit, case, PV connectors are on this non UL unit and if it is actually properly grounded.
 
Last edited:
Bud Martin said:
Since that inverter is grid-tie, I wonder what kind of leakage current on the exposed terminals of the unit, case, PV connectors are on this non UL unit and if it is actually properly grounded.
Click to expand...

i dont understand leakage current, is it like one of the factor for the power loss?

when i first set it up, i did a quick measure between the two ends, from DC to AC, i think it was like around 75% to 80%, which i thought was ok. most of the time, i just monitor from the AC side. for example today, i peaked at 495w from 2x 315w panels.
 

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You can have AC leakage current from the AC utility which is connected to your unit with that 3-prong AC plug to the internal circuit which is supposed to be isolated from the utility side of the circuit.
1) I would check the resistance between the case and the AC Safety ground prong of the unit to see if it shows <1 Ohms.
2) I would set your DMM to ACV then check the Ac Voltage between the case of the unit and the Safety ground prong of you AC Wall outlet and see what you get.
3) I would set your DMM to ACV then check the Ac Voltage between the Red terminal of the unit and the Safety ground prong of you AC Wall outlet, do the same test on the Black terminal to see what you get.
4) They can also have Line and Neutral on the AC connector wired it wrong too.
 
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